Most powerful and most expensive passports 2018

Germany has retained its position as the world's most powerful passport for 2018, while Australia leads the way as one of the world's most expensive.

The rankings are based on how many countries a passport holder can visit without requiring a visa.

The Australian passport remains unchanged from last year's rankings as the seventh most powerful in the world, tied with New Zealand and Greece, though the number of countries Australians can visit visa-free increased by one.

Australians can now visit 171 countries visa-free, up from 170 in 2017, after the visa requirement for Qatar was waived back in August last year. Other top-ranking countries include Switzerland and Singapore (176), Japan and the UK (175) and Spain and the USA (174).

Those languishing at the bottom of the heap include Afghanistan (24), Iraq (27) and Syria (28).

Formerly costing $11, the Syrian passport is now the most expensive travel document in the world, costing its citizens outside of the country $500 to obtain from an overseas consulate. That cost rises to $US800 if it's an emergency.

The world's next most expensive passport is Australia's. The cost rose $5 on January 1 to $282, according to a report by the New Daily.

Meanwhile, the passport to give you most bang for your buck in 2018 remained Germany's, the world's most powerful, costing $120 and allowing citizens to visit 177 countries visa-free.

The world's cheapest passport is the Tunisian – ranked 69th most powerful in the world, and allowing its citizens access to 66 countries visa-free and costing a mere $25.